Filter dyes are widely used in photographic elements and can be located in various locations in an element to absorb undesired light. In certain black and white photographic elements, such as film, it is desirable to be able to load the film into the camera, or other imaging device, under standard room light conditions. To prevent fogging of the photographic element, a filter layer that absorbs across the entire visible spectrum is provided. The filter layer contains one or more dispersed filter dyes to provide the desired absorption. The filter layer is typically positioned between the support and the light sensitive layer(s) of the photographic element or on the back side of the support. In particular, the filter dyes can be located in an antihalation layer or a pelloid layer.
A filter dye that is used in such a filter dye layer in commercial microfilm to permit room light loading of the film is disclosed in U.S. Pat. No. 4,092,168 ("the '168 patent"). However, filter dyes of the type disclosed in the '168 patent have been found to result in loss of speed of the film, when the photographic element is stored prior to exposure under elevated temperatures, e.g., above about 20.degree. C., and high relative humidity conditions, i.e., relative humidity above about 50%. This is particularly true when the light sensitive layer(s) of the photographic element is sensitized with certain red sensitizing dyes.
Microfilm can be used with various computer output devices, such as writers, that utilize a cathode ray tube, light emitting diode, laser or other light source to form the desired image on the microfilm. In a recently developed writer, a LED that emits light at a wavelength of about 680 nm is used. Microfilm for use with this writer contains a layer sensitive to light of this wavelength. The use of a filter dye of the type disclosed in the '168 patent does not adequately protect the light sensitive layer from light having a wavelength of about 680 nm and thus does not adequately protect the light sensitive layer when the film is loaded under room light into the writer. Further the film tends to lose speed if stored under high temperature and high relative humidity conditions.